Tangent (tan). A trigonometric function comparing
two sides of a right triangle as follows:
Tan = opposite side/adjacent side

Tap. Instrument used to cut threads on the inside of
a hole.

Tare weight. The weight of any chocks or devices used
to hold an aircraft on scales when it is weighed. The
tare weight must be subtracted from the scale reading
to get the net weight of the aircraft.

Tempering. Process that reduces the brittleness
imparted by hardening and produces definite physical
properties within the steel. Tempering always follows,
never precedes, the hardening operation.

Thermal expansion. The increase in size of a material
as temperature increases.

Tolerance. The sum of the plus and minus allowance
figures.

Torque. The tendency of a force to cause or change
rotational motion of a body.

Transformer. A device that changes electrical energy
of a given voltage into electrical energy at a different
voltage level. It consists of two coils that are not electrically
connected, but arranged so that the magnetic field
surrounding one coil cuts through the other coil.

Transistor. A three-terminal device primarily used to
amplify signals and control current within a circuit.

Trapezoid. A four-sided figure with one pair of parallel
sides.

True power. The power dissipated in the resistance of
a circuit, or the power actually used in the circuit.

Triangle. A three-sided figure in which the sum of the
three angles equal 180°.

Trigonometry. The study of the relationships between
the angles and sides of a triangle.

Type Certificate Data Sheet (TCDS). The FAA issues
a type certificate when a new aircraft, engine, propeller,
etc., is found to meet safety standards set forth by the
FAA. The TCDS lists the specifications, conditions and
limitations under which airworthiness requirements
were met for the specified product, such as engine make
and model, fuel type, engine limits, airspeed limits,
maximum weight, minimum crew, etc.